Project 3 Project Leader: Davis, Ronald L. Project Summary / Abstract The goal of this research is to identify the microRNA genes in Drosophila that mediate the process of learning and memory. We will continue a large genetic screen, surveying the importance of hundreds of microRNA genes, for their participation in short-, intermediate-, and long-term memory. These efforts will identify the subset of microRNA genes that have a functional involvement in memory formation, and perhaps in different temporal phases of olfactory memory. We will also study in great detail two microRNA genes that we have already discovered to improve memory when the microRNA gene function is impaired. Because impairing the gene improves memory, the normal function of the unimpaired genes must be as ?memory suppressor? genes. There are few genes known that can improve memory, so our research holds great promise for potentially identifying therapeutic targets for memory disorders. Our research studies are embedded in a large, collaborative project with other investigators who are studying microRNA genes for roles in sleep, locomotor activity, and synapse structure and function. The combined results will provide a broad understanding of how microRNAs underlie behavior through their functions in the central nervous system.